Led by Dr. Mitchell Machtay, chairman of radiation oncology at University Hospitals Case Medical Center and Case Western Reserve University School of Medicine, a clinical trial at 60 cancer centers across the country enrolled 250 people with Stage 3 lung cancer. The researchers used PET scans before and after a combined treatment regimen of chemotherapy and radiation to identify which patients had more aggressive tumors that required additional treatment.
They measured how rapidly tumors absorb a radioactive sugar molecule (known as FDG). Since most cancer cells take up sugar at a higher rate than normal cells, areas of tumor typically light up brightly on PET scans. Not only can it detect a tumor's size, PET scans also show what's going on inside of a tumor, such as changes in metabolic and chemical activity that are caused by actively growing cancer cells.
What the researchers found was that the PET scan patients received after their treatment were able to show that patients with high levels of FDG uptake following treatment had more aggressive tumors that were more likely to recur -- a poor indication for a patient's survival.The results also showed a strong correlation between the intensity of the radiation dose and how well the cancer was managed, suggesting the need for further research in the use of radiation technology for lung cancer.
"These findings have the potential to give cancer physicians a new tool to more effectively tailor treatments for patients with locally advanced lung cancer,” said Machtay, study author and principal investigator of the trial. “[The Radiation
Therapy Oncology Group] study determined that the PET scan can show us which patients have the most aggressive tumors, potentially enabling us to intensify their treatment.”
Lung cancer is the leading cause of cancer death in men and women in the United States and the second most common type of cancer. About 228,190 new cases of lung cancer, and about 159,480 deaths from the disease, will occur in 2013, according to the National Cancer Institute, which paid for the trial.